How can I animate bump or displacement node?
Of course you can animates all the settings you want in your nodes, you just need to put your cursor where you want the change to happen in the Timeline, then in the Node Editor put your mouse on the factor you want to change and press i to insert a keyframe. Now, move your cursor in the Timeline and again go back in the Node Editor, change the factor and press i to insert a new keyframe, etc.